//
//  UIImage+ZBScaling.m
//  PaoPao
//
//  Created by xzb on 2018/4/21.
//  Copyright © 2018年 paopao. All rights reserved.
//

#import "UIImage+ZBScaling.h"

@implementation UIImage (ZBScaling)


- (UIImage *)handleUpload
{
    return [self imageByScalingForValue:240.0];
}

- (UIImage *)imageByScalingForValue:(CGFloat)value
{
    if (value == 0) {
        return nil;
    }
     UIImage *scaleImage = nil;
    
    NSInteger oldWidth = CGImageGetWidth(self.CGImage);
    NSInteger oldHeight = CGImageGetHeight(self.CGImage);
    int newWidth = 0;
    int newHeight =0;
    if (oldHeight > oldWidth)
    {
        float rate = oldHeight/value;
        newWidth = oldWidth/rate;
        newHeight = value;
    }
    else
    {
        float rate = oldWidth/value;
        newHeight = oldHeight/rate;
        newWidth = value;
    }
    scaleImage = [self imageByScalingAndCroppingForSize:CGSizeMake(newWidth, newHeight)];
    
    return scaleImage;
}

- (UIImage*)imageByScalingAndCroppingForSize:(CGSize)targetSize
{
    UIImage *sourceImage = self;
    UIImage *newImage = nil;
    CGSize imageSize = sourceImage.size;
    CGFloat width = imageSize.width;
    CGFloat height = imageSize.height;
    CGFloat targetWidth = targetSize.width;
    CGFloat targetHeight = targetSize.height;
    CGFloat scaleFactor = 0.0;
    CGFloat scaledWidth = targetWidth;
    CGFloat scaledHeight = targetHeight;
    CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
    if (CGSizeEqualToSize(imageSize, targetSize) == NO)
    {
        CGFloat widthFactor = targetWidth / width;
        CGFloat heightFactor = targetHeight / height;
        if (widthFactor > heightFactor)
            scaleFactor = widthFactor; // scale to fit height
        else
            scaleFactor = heightFactor; // scale to fit width
        scaledWidth= width * scaleFactor;
        scaledHeight = height * scaleFactor;
        // center the image
        if (widthFactor > heightFactor)
        {
            thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
        }
        else if (widthFactor < heightFactor)
        {
            thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
        }
    }
    
    UIGraphicsBeginImageContextWithOptions(targetSize, YES, 1);
    CGRect thumbnailRect = CGRectZero;
    thumbnailRect.origin = thumbnailPoint;
    thumbnailRect.size.width= scaledWidth;
    thumbnailRect.size.height = scaledHeight;
    [sourceImage drawInRect:thumbnailRect];
    newImage = UIGraphicsGetImageFromCurrentImageContext();
    //pop the context to get back to the default
    UIGraphicsEndImageContext();
    return newImage;
}

@end
